In the assembly of fluid flow controlling systems, pipes and other cylindrical objects are typically joined with other pipes by means of welding or by means of flanged joints which are bolted in assembly. This invention relates particularly to apparatus which is utilized for joining pipes, pressure vessels and other objects in interconnected assembly by means of welding.
Since pipes and other such objects are frequently joined in assembly by welding, most experienced welders have been taught to manually lay out and cut openings in pipes for the connection of other pipes thereto. In this case, welders also learn to prepare end preparation on the pipes to be joined, thus permitting the pipes to be placed in intimate, closely fitting relation to permit efficient welding. Manual layout of holes in pipes and end preparations for the pipes to be joined therewith is obviously a time consuming procedure and is thus considered sufficiently expensive as to be detrimental. For this reason, over the years, many mechanical devices have been developed for the purpose of achieving pipe opening layout and pipe end preparation. In some cases, the pipe cutting apparatus is guided on the outer surface of the pipe to achieve proper torch positioning and in other cases it is guided by cam induced systems to maintain accurate positioning of a cutting torch in relation with the outer surface of the pipe being cut.